Breast form



Feb. 20, 1951 E. H. BERNHARDT BREAST FORM Filed May '7, 1949 JNVENTOILt' 3 AWO/@N957 Patented Feb. 20, 1951 UNITED STATES yP A';.";NT1()fl;"l"lCE BREAST FORM yElla H. Bernhardt, New York, X.Application-May 7, 1949, serial No. 91,961 anonime. (cina-2.67.)

"'I-he present invention .relatesto prosthetic de vices and moreparticularly to a conformable breast form containinga quantity of a.liquider a `conformable gel. This `application is a.continuation-in-part of :my ico-pending application Serial No. 28,563,filed May 22, 1943.

The breast forms are especially designedforiuse as a breast form after asurgiCalopeIatiOn. In such cases the figure of the -personfoftenpresents an unpleasing appearance and the formgisworn to maintain thenormal figure `orontline yof vthe bust. In other instances, theformsare'worn by Women with vsmall underdeveloped :breasts fin order toimprove theirfgures.

It is important that the form be :conformable to the shape of the breastoriremainder lof ,the breast of the wearergan'd of `proper Weightsoxthat it may be Worn for long periods 'of -time Without discomfort.Further, the form should be so constructed that it constantly .andautomaticallygconforms to the remaining breast in shape-and appearance,as that breast risalfected `by the position assumed by the wearer.

Heretofore, some forms have been-made of wire reinforced padding, others`have 'been made 4of flexible fabric stuffed Withalling such'as hair,feathers or cotton, still othershave been'molded of sponge rubber, inaddition, air lled sacs and distendible sacs inflated with water havebeen used. These devices all have a relatively `fixed shape, and 'arelatively constant volume, or are rather inconformable and ido notrealistically reproduce the change in shape and the movement of a normalbreast. Some of the prior devices have been generally satisfactory foruse when the wearer is in a standingposition and not in motion. However,when the wearer assumesa Vsitting or prone position,ior takes lpart inexercise, the movement of `the prior art appliances are often unnaturaland uncomfortable inasmuch ,as ,these appliances ,do not .duplicate thechanging shape of the remaining breast. The unnatural and uncomfortableposition ofthe appliance is especially noticeable in Women of middle agewho `make up the greater percentage of those with surgicaly removedbreasts. The apparent Waist portion of an average person shortens aboutone to ytvvo inches when the person isseategd. The apparent shorteningis more pronounced inpatients with faulty posture such as isfrequentlyassumed post-operatively. The full slanting Vdiaphragm and often largeabdomen pushes the usual appliance still higher whenthe person isseated. 'lo counteract this movement, straps engaging with the corset orgirdle are often used tofpull therapmance-downwardly. .'Ihe.(strainsetup by such 'st-raps not only y.causes discomfort at `the shouldersrbntactuallyserousiydnterferesfwithfthecirs culation oishoulder .andarm andbecause of the recent operation often produces congestion Moreover, vinfmany tosses, the prior appliances have been dinicultsor `impossible tocleanfor'ren.- ovate and `When-'sofcleaned often losetheir-.prginalshapeeand presentfan Aunsightly appearance. The L'present invention:aims lIto lovercome :the foregoing diliiculties and disadvantages by.rpro viding .1a-form whch'is-more :natural :in appear.- a-nce andreadily conforms 'to 'the Yshape -of the natural bust regardless'ofthemovements of the wearer, andV that requires -no special 'harness towea-r.

Another Yobject'o'f "theinvention is to provide a 'form Awhich issanitary, `.and Which may *be Washed easily and `repeatedly 4Withoutadversely affecting its `Wea-rability.

These objects are accomplished by providing a conformable cell, atleastpartially lled with a liguid, or aconformable Agelfa'nd a-'gas The cellisadapted lto ,be carriedinfthe unmodied cup of an ordinary brassire,-or-in a brassire cupprovided with a retainer, or in the ordinaryitypeof form-fitting .bathing suit, so that inuse, the c ell isconformedtoithe-shape'an'd volume ofthe availablespace `between the brassire, and'the breast ror the ,remainder of the breast, so as ,to produce thedesired appearance. BY .reason of the iillingmateriaLand,the amountused,..the cell is notdistended lor `xeldlin -shane but vautomaticallyassumes the .shapeandcontour of thenormal breast regardless of theposition or movement ofthe wearer.

AIn -anothenconstruction ,the liquid filling. material .includesaAfoaming agent, Aso that under normal bodily movements, no y.appreciablesound caused byra movementof .thecontents `mais' bedetested.

In f another kconstructicn tof .the form, .it enclosed in an `outerIprotecting envelope s oas .to prevent ,asudden;escapeiof-,theliquid inthe .event of ,apuncturezorfruptureof:the `retaining.celllzanglthenllingimaterialjincludesfan ,agent-that coagulates upon evaporation,thus-this cell issubstam tialy as elffsalng,

ln .anctherrconstruction -of the inventrl a cellular :structure is.provided within the retain- Iilg C611 So :as wto impede fthe movement:of fthe liquid.-and-thnsitofcauserthe form to more nearly simulate thenormal movements of the natural zbtlast..

with which it is used or worn, regardless of its style, whetheruplifted, pointed, rounded or pendulous, thus the wearer may use abrassire of the same style as worn before the breast removal and beassured that the outer clothing will fit without alterations.

appearance areY important improvements over prior appliances.

conforms to the shape .of the cavity left by the breast removal, andaccordingly the appliance may be worn soon after an operation while tisesues are still sensitive. Moreover, the breast form because of itssmooth and'fiowing characteristics protects the sensitive area andprevents friction thereon from the movement of the arms or clothing. Theform quickly assumes .the body temperature and is Ymore "comfortabletothe wearer" asv it'radiates heat and feels .co'oler 1than many of theprior appliances. As `its weight is approximately that 'of the nonmalbreast, no straps or other means Yare needed to holdit in position andits weight has a compensating effect inhelping toovercome unequalshoulder carriage, which is a frequent result of a major mastectomy. in*The correctweight of the breast form reestablishes body balance. After amajor mastectomy,

aylack of such balance results invphysical in stability which oftencauses mental instabilities and phobias in patients, such as fearv offalling when descending stairs, and fear of walliing on wet streets. l AY.

I, Other objects and advantages of the invention will be apparent fromthe following description and from the accompanying 'drawings .whichshow, by way of example; embodimentsfof the invention.

,1 In the drawings:

Fig. 1 isa perspective View of a breastform worn with a brassire andshown in position on af female figure, the conformableY cell being po.

sitioned in a pocket in the brassire v.and outlined in dotted lines.

Fig. 2 is a partial plan viewof the cell. j. Fig. 3 is a cross sectionalview of the cell and brassire taken substantially 'along the line 3-3`of Fig. 1.

Fig. 4 is a view corresponding to Fig. 3 of a modified form of the celshowing a cellular structure within the cell formed ofv a plurality ofsmall cells in liquid.

Fig. 5 is a View corresponding to Fig. 3 of a modified form of the cellshowing a cellular `structure within the cell formed of a plurality ofpieces of a sponge-like material in liquid.

Fig; 6 isa View corresponding to Fig. 3 of a "modified 'form of thecell-showing a protective "envelope enclosing the cell, the cell beingfilled 'with a preferred liquid.

Referring to the drawings, in' Fig. 1 the .con- 'formable cell Ill,indicated in dotted lines, is

located in the brassire 'cup I2 of brassire I3 "adapted to support andconform said cell, the Iassembly being worn on the .female form asshown.

The brassire I3 may be of any suitable form Further, thefforrn hassmooth and flowing characteristics and thereforel readily,

4 and is preferably of the same type or shape as worn by the wearerbefore the mastectomy.

As shown in Fig. 3 the brassire cup I2 is provided with a cell retainerI5 which may be a piece of soft textile material sewn along the sidesand bottom of the inside of the brassire cup. A flap I5 is provided tocover the opening at the top of the brassire cup.

Y, As canY best be understood by a comparison of Figs. 2 and 4, the cellIn has a front wall I'I and a back wall I8, formed from a waterimpervious Aflexible sheet material, the peripheries of the My breastforms mobilityj and softness to touch as well as its.. improved wallsare joined together and sealed along the .line I9. Alternately, the cellmay be molded'in brassire cup. The rear wall I8 is generally fiat thoughit may also be convex-concave if worn as a breast form overunderdeveloped breasts, or may be concave-convex if meant to ll aparticularly large cavity resulting from a.y major operation.

In Fig. 2, end 20 of the cell, shown as broken away, may be extended ormodified as necessary to fit'along the axillary side of the wearer tofill a surgical' cavity which may extend in that direction.

As shown in Fig. 2, an unsealed portion 2I of the cell Ill is providedas a means of placing the contents in the cell. After this operation,this portion 2| is sealed.

As shown in Fig. 3 the cell Ill is at least partially filled with aconformable filler II, which may be a liquid or a conformable gel, andgas 22 atatmospheric pressure.

Another embodiment of my invention is as shownin Fig. 4. in which thecell, constructed as above described, is at least .partially lled with aplurality of small cells 23 of preferably ellipsoidal shape. Each of thecells 23 is at least partially filled with conformable filler II whichmaybe a liquid or a conformable gel, and a gas 22 at atmosphericpressure. l Surrounding the cells 23 is ller II, which is a liquid; toprovide lubrication and other desirable qualities as will later appear.The cell Il) is thus partially filled with the cells 23, and liquidfiller I I and gas 22 at atmospheric pressure.

' front wall 26, and a rear wall 21, made of a flexibleuid imperviousmaterial, the front and rear *walls being joined at their respectiveperipheries and sealed along the line 23. Alternately the envelope maybe molded in onel piece. The envelope 25 contains cell I0 plus a smallquantity of gas 22v at atmospheric pressure. The envelope 25 may alsocontain a quantity of a highly water 'absorbent powdensuch as bentonite(not shown).

vNote that in Fig. 6, the liquid filler I I and gas 22 .contained incell IB, is .shown in a foaming condition 29. A conformable gel may alsobe used to fill cell I6.

' It is of course apparent thatthe embodiment shown in Figs. 3, 4 and 5,may be combined with the outer envelope shown in Fig. 6, and asdescribed above.

"l'lreiwalls c'f 4fthe cells, `both small .rand liar-ge. and theenvelope described above, asin iFig. .6, $arefmadfe of la :flexible'sheet material `that is fimfpelivious vto -the passageio'f waterorfair. :My preferred-material is affiexible'sheet of thematerial knownas Vinylite "This material is la highly `nplastieized copolymer :ofvin-ylchloride rand .vinyl 'acetate resin, and has the advantages :of`being Vcheaper and vmore 1frame resistant than rubber, Eis :flexible atbody temperature, and is resistant 'to the action'of body perspiration..Ihave found Ithat use of Vinylite -sheet stock twelve .thousandths ofan inch (0.0l2) thick results `rin a 'cell that is 4strong and durable,Yand commercially satisfactory.

'The walls of vthe cell are joined vtogether by `cementing, or if the:material is Vinylite, by w`sealingthe edges together by the "so-calledelecitronic 'sealing method `which makesY use ofV high frequencyvcurrents to accomplish the heat sealvIng.

The contents of the cell `are Acomposed of gas fa't'atmosphericpressure, and a fillerwhich may be a liquid orf-a conformable gel.v'Where hereinfafter inthe claims or the specification. the wordsconformable ller'are used, it is intended to fmean'both a liquid 4and aconformable gel. These materials are incompressible, 'as 'distinguishedfrom materialslike sponge rubber, and substan- "tially inexpansible asdistinguished from gases. My .preferred liquidifs water, to which vImayadd aa 'foaming :agent and ra Vsealing agent. When "less'thancallof alcell .is filled with a liquid, the liquid sloshes about andmakesfaddible :sounds .when 'the .icell is :moved Thus ia .foamingagent, which ,reduces these sounds to .substantial in- -aiudi'bility,.overcomes .fthejgreat 'disadvantage of :a 'flexible cell ,partiallyfilled Withca liquid. The advantages of incorporatingza sealing agent,in :case'df a puncture or ,corrosionzor rotting of the :cell walls, isobvious. "Other liquids which `may be used are; oils, emulsions ofcil-and wateigsoap mixtures, `thickened oils, suspensions landemulssions inzoil'and'water,.siliconjliquids such asDow- Corning DC 200silicon `fluid (a heat-stable, or

gano-'silicon oxide polymer), 'and liquid latex.

I have found that `the material known as ,Vinylseal adhesive Vif-125,which .is a water- `solublefplastic resin, containing minimum solids 'ofabout 5.0 %.by`weight, of :which 1.5% .by weight monomeric vinylacetate, and having a vis- `cosity:exceeding300.0 centipoises, a pH of4.5-to 5.0 and a weight ofz925llbs. per gallon .atGGo F.,

aand Ywhich is sold as "an adhesive, also -has `the property `of:foaming when mixed with water tand fagitated. ,Thismixture will Valsocoagulate lon evaporation, and when :containedin the cell, itheellbengpunctured, the mixture will function to seal .the puncture. .The'fself:sealing efl ,feetzlisparticularlygoed when the cellzis a secondenvelope `(as shown .LingFig 6). When the .double 'cell Yis puncture@fierylittle .liquid eescapes completely, las most of it spreads in athin film between the walls, and quickly forms a sealing C1011-conditionby thef normalimovements 'of'zthe .wearerfofithezform, andiwill scalrsatisfactorily. Variations of the above proportions of water:and Vinylseal adhesive Nif-'125, may be used .depending lon theviscosity, foaming characteristics, and 'sealing qualities desired.

An `amount of liquid or conformable vgel filler is usedthat willapproximate the Weight of tissue that has .been removed. An amount ofgas at atmospheric pressure, preferably air, is also allowed 4in .thecell .before sealing, 'this amount of air is necessary so that theliquid mixtures may foam :and `also to produce a cell that can changelin "vo-lumeunder pressure, and that `will reproduce a'volume underpressure correspondring to the volume of tissue lacking.

Inorder toachieve a comfortable, conformable cell, thepossible'total'volume of the cell is generally not entirely utilized.Ilhis :is simply .accomplished by pressing a portion of the walls ofthecell together :after the conformable filler has been put .in "the cell,and during the `:final sealing step. The amount of conformable fillergenerallyxshould noti-lll theavailable space, some space being 'left forair. The cell'is sealed with the entrapped liquid or conformable gel andair 'generally filling only a portion of the total possible volume o'fthe cell.

As an example, 'inzmy manufacture of cells for certainprosthetic'uses,not requiring special individual "fitting, I have 'found that it isnecessary fto provide a Vcomplete range :of sizes for both `left andfright breasts. kOf course, teach size breast is different rinweightarfd shape r.from the other. The cells all have flat back walls,the Wall material ibeing conformable enough to ll in around uneven scartissue Iformations 'over ^the chest, and "at the axillary region.

However, AI have found Vthat in manufacturing all these ready-made formsthat the proportions `of gas and Aconformable filler are -about thesame. I generally fill each cell full (of its possible total volume)with conformable ller, and leave 'approximately '10% to 15% of thecellvolume fasfdead* space. The remainder Vof the possible volume of thecell, i. e., between 25% and 12.01% y is `lled with air 'at aboutatmospheric pressure.

Tnmy manufacture of ycells for cosmetic pur- -posesfthe'cellsare'different in shapeand weight than the aforementioned cells.

'As shown in :my examplesin Figs. 3 and `6, Aa conformable gel may `beused to partially fill the 'cell 1l. vlThe conformable gel is used asabove described for the use of liquid. A `suitvale conformable gelmaterial is the product known as "Bouncing Putty grade 9991-41manufactured by the General Electric Comfpany. :'Said Bouncing Putty maybe modified with oil, .greasy'substances Aor substances lcon- 'A's shownin my example in Fig. 4, the small cells 23 may be partially filled withconformable fgelin place of liquid. while the cell Il is par- `tiallyTilledwith liquid.

ABy reason o'f the plurality of `cells shownin .Fig '4, or the cellularmaterial shown in Fig `5,

contained in the .retaining cell, a somewhat :more gradual :change .in"the shape of theretaining cell `occurs fas Vthe wearer assumesdifvpressure at least partially filling the ferent positions; Thesecells thus very closely approximate the shape changes of the normalbreast. Y

Having thus described my invention, I claim:

1. A breast form comprising a conformable retaining cell, a conformable,incompressible, inexpansible iiller and a gas at approximatelyatmospheric pressure in said cell, the combined volumes of said filledand gas at least partially filling the cell. 2. A breast form comprisinga conformable retaining cell, a conformable incompressible ller and agas at approximately atmospheric pressure in said cell, the combinedvolumes of said filler and gas at least partially filling the cell, andthe Weight per unit volume of said gas and filler approximatelyequalling the weight per unit volume of human tissue.

3. A breast form comprising a conformable retaining cell, a liquid and agas at approximately atmospheric pressure in said cell, the combinedvolumes at least partially filling said cell.

4. The breast form of claim 1, wherein said ller is a liquid adapted tocoagulate upon evaporation.

5. The breast form of claim 4 enclosed in a flexible envelope imperviousto fluids whereby the cell will seal itself when punctured. K

6. A breast form comprising a conformable retaining cell, a foamingliquid adapted to coagulate upon evaporation and a gas at approximatelyatmospheric pressure in said cell, the combined volumes at leastpartially filling said cell. i

'7.' The breast form of claim 1, wherein said ller is a conformable gel.

8. A breast form comprising a'conformable retaining cell, a plurality ofpieces of spongelike material, and "a liquid, and a gas at approximatelyatmospheric pressure in said cell, the combined volumes at leastpartially filling said cell.

9. The breast form of claim 8 wherein the liquid is a foaming liquidadapted to coagulate upon evaporation. and said cell is enclosed in aflexible envelope impervious to fluids. l0. A breast form comprising aconformable retaining cell, a plurality of smaller cells in said cell, aconformable' ller and a gas at approximately atmospheric pressure atleast partially ,filling the smaller cells, said smaller cellsand 'aliquid and a gas at approximately atmospheric remaining volume in theretaining cell.

11. The breast form of Claim'lO wherein-*the conformable filler and theliquid is a foaming lliquid adapted to coagulate upon evaporation.

' 12. The breast form of claim 2'enclosed in a flexible envelopeimpervious tofluids. n

13. A breast form comprising a'lconformable retaining cell, a mixture ofwater, a'watersolvent resin adapted to`foain upon agitation and tocoagulate upon evaporation, and a'gas at approximately atmosphericpressure in 'Said cell, the combined volumes at least partially fillingsaid cell. Y 14. A breast form having front and rear Wall formed from aflexible sheet of resin'comprising the -plasticized copolymers o'fvinylchloride andvinyl acetate, a mixture of Water, a Water ksolvent resinadapted to foam upon agitation and to ccagulate upon evaporation, and agas at approximately atmospheric pressure `in said cell, the combinedvolumes at least partially lling said cell.

15.l The breast form of claim 14 enclosed in an envelope having frontand rear Walls formed from a flexible sheet of resin comprising theplasticized copolymers of vinyl chloride and vinyl acetate. Y

16. A breast form comprising a conformable retaining cell, said Cellhaving front and rear walls formed of flexible sheet Vinylite, amixtureof Water, Vinylseal Adhesive W-125, and a gas at approximatelyatmospheric pressure in said cell, the combined volumes at leastpartially lling said cell.

1' 7. The breast form of claim 16 in which the proportions of water andVinylseal adhesive W-125, are approximately equal to each other.

18. A breast form comprising a conformable retaining cell, a conformableller and a gas at approximately atmospheric pressure in said cell, thecombined volumes of said ller and gas at least partially lling the cell,said cell being enclosed in a flexible envelope impervious to fluids,and a highly liquid-absorbent material contained within said envelopeand Without said cell.

19. In combination with a brassire, a exible retaining cell, and afoaming uid at least partially lling the cell, the brassire conformingthe flexible cell to the desired shape.

20. In combination with a brassire, a flexible retaining cell, fluid atleast partially lling the cell, and an envelope impervious to the fluid,the envelope enclosing the cell, the brassire conforming the envelopeand the fluid filled cell to the desired shape.

21. In combination with a brassire having a pocket therein, a flexibleretaining cell, and a foaming fluid at least partially filling the cell,the pocket supporting the uid filled cell and 'the brassire conformingit to the desired shape.

22. In combination with a brassire, a flexible retaining cell, acellular structure within the fluid retaining cell, and fluid at leastpartially lling the cell and lling and surrounding the cellularstructure, the retaining cell conformed to the desired shape by thebrassire.

23. In combination with a brassire, a flexible retaining cell, acellular structure Within the fluid retainingV cell, iiuid at leastpartially filling the cell and filling and surrounding the cellularstructure, and an envelope impervious to the fluid enclosed in the fluidretaining cell, the retaining cell and the envelope conformed to thedesired shape by the brassire.

24. In combination with a brassire, a flexible retaining cell, aplurality of smaller cells, fluid at least partially filling the smallercells, the smaller cells enclosed within the retaining cell, and "fluidat least partially filling the remaining space in the retaining cell,theretaining .cell conformed to the desired shape by the brassire.

25,'1In combination with a brassire, a flexible retaining cell, aplurality of smaller cells, fluid at least partially filling the smallercells, vthe smaller cells enclosed Within the retaining cell, iiuidatleast partially filling the remaining space in the retaining cell, andan envelope impervious 'tothe fluid enclosed in the fluid retainingcell, "theretaining cell and the envelope conformed the desired shape bythe brassire.

the cell, and an envelope impervious to liquid and complet,ly enclosingthe uid cell.

28. An articial breast form comprising a flexible retaining cell, acellular structure Within the cell, and substantially incompressible uidat least partially filling the retaining cell and filling andsurrounding the cellular structure.

29. An artificial breast form comprising a exible retaining cell, acellular structure within the cell, fluid at least partially filling theretaining cell and filling and surrounding the cellular structure, andan envelope impervious to the fluid enclosed in the fluid retainingcell.

30. An artificial breast form comprising a flexible retaining cell, aplurality of smaller cells, a substantially incompressible fluid atleast par-V tially filling the smaller cells, the smaller cells enclosdWithin the retaining cell, and uid at least partially filling theremaining space in the retaining cell.

3l. An artificial breast form comprising a flexible retaining cell, aplurality of smaller cells, fluid at least partially lling the smallercells, the smaller cells enclosed within the retaining cell, fluid atleast partially filling the remaining space in the retaining cell, andan envelope imperious to the fluid enclosed in the fluid retaining cell.

32. A breast form comprising a liquid impervious cell of flexiblematerial, a conformable liquid ller and a gas at approximatelyatmospheric pressure within said cell, said ller being substantiallynoiseless when agitated by normal body motions, the said ller occupyinga major portion of the volume of said cell and the combined volume ofsaid ller and gas being less than the total possible volume of saidcell, and a flexible envelope of material impervious to said fillerfitting loosely around said cell whereby upon accidental rupture of saidcell, the leaked portions of said ller are retained within saidenvelope.

33. A breast form comprising a liquid impervious cell of flexiblematerial, a conformable liquid filler and a gas at approximatelyatmospheric pressure within said cell, said ller being substantiallynoiseless when agitated by normal body motions, the volume of saidfiller being approximately 80% of the total possible volume of said celland the Volume of said gas being approximately 30% of said totalpossible volume, and a iiexible envelope of material impervious to saidfiller fitting loosely around said cell Whereby upon accidental ruptureof said cell, the leaked portions of said filler are retained withinsaid envelope.

34. A breast form comprising a liquid impervious cell of flexiblematerial, a conformable liquid filler and a gas at approximatelyatmospheric pressure Within said cell, said filler being substantiallynoiseless when agitated by normal body motions, the combined volumes ofsaid filler and gas bling less than the total possible volume of saidcell, the combined weight per unit of their total volume of said gas andller approximately equalling the weight per unit volume of human tissue,and a flexible envelope of material impervious to said filler ttingloosely around said cell whereby upon accidental rupture of said cell,the leaked portions of said filler are retained within said envelope.

35. A breast form comprising a liquid impervious cell of flexiblematerial, a conformable liquid filler and a gas at approximatelyatmospheric pressure with said cell, said filler being substantiallynoiseless when agitated by normal body motions, the volume of saidfiller being approximately of the total possible volume of said cell andsaid gas being approximately 30% of said total possible volume, thecombined weight per unit of their total volume of said gas and llerapproximately equalling the Weight per unit volume of human tissue, anda flexible envelope of material impervious to said filler tting looselyaround said cell whereby upon accidental rupture of said cell, theleaked portions of said filler are retained within said envelope.

36. An artificial breast form comprising a ilexible retaining cell and aconformable gel at least partially lling said cell, said gel comprisingBouncing Putty.

ELLA H. BERNHARDT.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 326,915 Morehouse Sept. 22, 1889599,180 Harrison Feb. 15, 1898 861,115 Harrison July 23, 1907 1,721,739Kennedy July 23, 1929 2,108,205 Martin Feb. 15, 1938 2,345,649 Zimmermanet al. Apr. 4, 1949 FOREIGN PATENTS Number Country Date 7,338 GreatBritain May 20, 1887

